Prestressing of Carbon Fiber Elements in Virginia

Prestressing of Carbon Fiber Elements in Virginia Tuesday, August 11, 2015, 1:30 PM – 3:00 PM E. Alan Saunders, PE, CCM VDOT Assistant State Construction Engineer

Corrosion Damaged Bridges

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One of the leading causes of bridge deterioration is corrosion of the steel.

In 2004, FHWA reported $10.5 billion in bridge rehabilitation

Improvements at VDOT

VDOT has improved the corrosion resistance of steel reinforced bridge decks using CRR

Next comes improvements to prestressed elements.

Thousands of pounds of stainless CRR for placement in PCUs

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Carbon Fiber Composite Cable (CFCC) or Carbon Fiber

Reinforced Polymer (CFRP)

Directionally Strong Corrosion Free Lightweight

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CFCC Strand Spiral

CFCC Properties

Property Value Tensile strength (min) 338 ksi Elastic Modulus 22,500 ksi Elongation at break 1.7% Specific gravity 1.6

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Maine Cable Stayed

Michigan Post Tensioned

CFCC Applications

More than 130 applications by 2009 Prestressed and Post-tensioning Suspension Bridge Main Cable Ground Anchor Stay Cable

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World’s First Bridge Using CFCC

Shinmiya Bridge Coastal Structure Replacement built in 1988 Underside now corrosion free

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Sea of Japan

Initial Bridge (20 yrs service)

Replacement (20 yrs service)

Initial CFCC Pile Research Plan

18 piles would be fabricated using carbon fiber composite cable reinforcement in place of traditional steel strand and spiral

Each pile would have16 strands 0.6 in diameter CFCC

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VDOT’s First Application

VDOT Nimmo Parkway in Virginia Beach 9

Pile Fabrication

Bayshore Concrete Products fabricated all the piles Two test piles would be

fabricated at facility in Cape Charles, VA

Remaining production piles would be fabricated at facility in Chesapeake, VA

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Overview of Casting Areas

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180-ft (Cape Charles) and 320-ft (Chesapeake) long beds with steam curing pipes at both plants

Production Piles

Test Piles

The Coupler (AKA. Double Chuck)

Several parts required to properly assemble coupler

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Strand Coupled

CFCC Details: No metal or sharp corners

Plastic Tie and Tubes Circular Spiral

Removable Lift Device

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Stressing

Stressed •5 kips •15 kips •25 kips •34 kips 14

Concrete Placement and Consolidation

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Rubber tipped vibrator ends

16 Couplers kept below 122 F

Pile Removed From Forms

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Piles are Transported to Site

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Preparing Piles for Driving Piles are lifted and

positioned for driving

During Driving Ram Weight

• 10,141 lbs

Hammer Stroke • 5.7 – 9.2 ft

Test piles were instrumented

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CFCC Reinforced Piles Summary

Success in fabrication and driving 2 test piles fabricated In Nov 2012 and

driven in Oct 2013 (11-month cycle) 16 production piles fabricated in Nov

2013 and driven in Dec 2013 (1-month cycle)

Driving response similar to steel reinforced pile

Successful Pile Design 24 inch square pile, with 5.7- mm (0.225-

in) CFCC spiral in a circular pattern 16 15.2-mm (0.6-in) strand/pile at 34

kips/strand 20

CFCC Reinforced Pile Parting Thoughts

Unlike steel strands Strand cost per foot

higher Preparing strands for

tensioning is slower No Buy America

requirement Corrosion free

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CFCC Beams

2 span bridge 4 beams per span 82-ft length beam

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Route 49 over Aaron’s Creek CFCC Beams

Aaron’s Creek CFCC Beams

Each beam is a 45” modified bulb tee girders

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Preparing CFCC Strand

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CFCC Tensioned and Beam Forms Closed

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Concrete prepared and Tested

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Concrete Placed and Finished

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Beams are Transported to Site and Erected

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CFCC Pile and Beam Summary

Corrosion free piles can be produced and driven using standard practices and equipment

Corrosion free modified bulb tee beams can be produced and erected also using standard practices and equipment

For both CFCC piles and modified bulb tee beams, some design and materials of construction modifications are required

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Current Challenges Industry

More competitors Eliminating delays in

bid response Minimize shipping

issues Use of SCC mixes to

reduce need for vibrator

Research Temperature or

coupler slippage concern

Improvements to end preparation time

Maximizing material use to reduce cost

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DOTs Define where higher cost AND higher benefit materials could be of value to the DOT and public

Prestressing of Carbon Fiber Elements in Virginia Questions: Celik Ozyildirim (Celik@vdot.virginia.gov) Stephen Sharp (Stephen.Sharp@vdot.virginia.gov) Acknowledgements: FHWA, VDOT Construction, VDOT Structure and Bridge, VDOT Materials Divisions, and Virginia Center for Transportation Innovation and Research